Fixed issue #383

Fixed issue#383. Added the check for null before submitting the request on ctrl+enter.
Deleted the old branch with PR#721 as it got messed up while rebasing from develop.
Gordon: Looks like with your fix for rcloud.comment.post for handling errors(https://github.com/att/rcloud/commit/4d64b09b9e6d825fccec4ac1254f1b10bf5423e9 has broken the basic post comment functionality ). So once you fix that my commit for handling cmd/ctrl+enter and null check will work properly as am internally calling the same function for posting comments.